EP1479346B1 - Surgical stapling instrument incorporating keyed firing mechanism - Google Patents

Abstract

A surgical severing and stapling instrument clamps tissue within an end effector of an elongate channel pivotally opposed by an anvil. An E-beam firing bar affirmatively maintains a desired spacing while severing and stapling tissue by longitudinally engaging the anvil and elongate channel. Separate closing action and firing (i.e., severing and stapling) action of the end effector allows a clinician to selectively position and clamp tissue. The end effector enables this advantageous separate firing while affirmatively spacing the end effector by having an upper pin of the firing bar reside within an anvil pocket before firing. When the anvil is closed and clamped, the upper pin of the E-beam firing bar may move longitudinally and distally from the anvil pocket to an anvil slot thereby engaging the anvil. <IMAGE> <IMAGE>

Description

Cross Reference to Related Applications
• The present application is related to four co-pending and commonly-owned applications, these four applications being respectively entitled:
1. (1) "SURGICAL STAPLING INSTRUMENT HAVING A SINGLE LOCKOUT MECHANISM" to Frederick E. Shelton IV, Mike Setser, and Bruce Weisenburgh (EP 1479348)
2. (2) "SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING & FIRING SYSTEMS" to Frederick E. Shelton, Mike Setser, and Brian J. Hemmelgam; (EP 1479349)
3. (3) "SURGICAL STAPLING INSTRUMENT HAVING A SPENT CARTRIDGE LOCKOUT" to Frederick E. Shelton IV, Mike Setser, Bruce Weisenburgh (EP 1479345); and
4. (4) "SURGICAL STAPLING INSTRUMENT HAVING A FIRING LOCKOUT FOR AN UNCLOSED ANVIL" to Frederick E. Shelton IV, Mike Setser, and Bruce Weisenburgh (EP 1479347).
Field of the Invention
• The present invention relates in general to surgical stapler instruments that are capable of applying lines of staples to tissue while cutting the tissue between those staple lines and, more particularly, to improvements relating to stapler instruments and improvements in processes for forming various components of such stapler instruments.
Background of the Invention
• Surgical staplers have been used in the prior art to simultaneously make a longitudinal incision in tissue and apply lines of staples on opposing sides of the incision. Such instruments commonly include a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument includes a plurality of reciprocating wedges which, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
• The simultaneous severing of tissue while forming rows of staples on each side of the cut reduces bleeding and simplifies the surgical procedure. However, an appropriate amount of tissue should be clamped between the jaws so that proper staple formation is achieved and so that a cutting member does not bind or otherwise fail to fully cut the clamped tissue.
• A stapling and severing instrument that maintains a maximum jaw spacing is described in U.S. Pat. No. 4,429,695. In particular, a central knife carrier has an upper shoe that enters an upper passageway through an opening when the upper jaw is closed and has a lower shoe that is received within a lower passageway of the lower jaw. Thus, as the knife carrier is advanced distally, the shoes vertically and laterally position the upper and lower jaws. U.S. Pat. No. 4,429,695 teaches that the shoes are attached to the central knife carrier to resist vertical deflection (opening) of the jaws during ejection and forming of staples. As taught, the forces tend to vertically open the jaws during stapling. However, no mention is made of resisting forces that might be applied to vertically close the jaws. Additionally, this reference teaches that the device described therein is assembled from two separate, unconnected elements that are brought together and clamped onto tissue. The two elements form a device suitable only for an open procedure that has no size limitations.
• Increasingly, endoscopic and laparoscopic procedures are preferred over open procedures due to their reduced post-operative recovery times and other advantages. Endoscopic stapling and severing instruments use a long slender jaw member that tends to deflect upwardly when clamped onto thick tissues. On thick tissue, this upward deflection of the free (distal) end of the jaw can cause differences in height of the formed staples as the distal gap between the anvil and cartridge is larger than the proximal gap. To ensure more uniform proximal to distal staple formation, the anvil is frequently cambered or bent inwardly toward the staple cartridge. This camber is better for thick tissue and can cause tighter staple forms at the distal end when used on thin tissue. To overcome this tight distal closure, pins or bumps have been added to the clamping surface of the cartridge adjacent to the distal end of the cartridge. The closure of the anvil onto the pin ensures a minimum gap at the distal end. However, surgeons were concerned about the pins or bumps causing tissue trauma. What is needed is a mechanism for maintaining a minimal gap between the anvil and cartridge and a mechanism for maintaining a maximum gap between the anvil and cartridge.
• An example of a surgical stapler suitable for endoscopic applications is described in U.S. Pat. No. 5,465,895, which advantageously provides distinct closing and firing actions. Thereby, a clinician is able to close the jaw members upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can then fire the surgical stapler, thereby severing and stapling the tissue. The simultaneous severing and stapling avoids complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever or staple.
• One specific advantage of being able to close upon tissue before firing is that the clinician is able to verify via an endoscope that a sufficient amount of tissue has been captured between opposing jaws. Otherwise, opposing jaws may be drawn too close together, especially pinching at their distal ends, and thus not effectively forming closed staples in the severed tissue. Moreover, a firing bar that traverses between opposing jaws to sever the tissue and to drive the wedges that drive the staples may encounter resistance due to the pinched opposing jaws.
• Thus, while such surgical staplers have been a significant advance in surgical procedures, an opportunity has been recognized for enhancing their effectiveness. In particular, it would be desirable to affirmatively maintain proper spacing between the opposing jaws during firing, both opening and closing deflections. In particular, endoscopic devices need to fit into an access device such a trocar, and must maintain a small shaft diameter. To date, no endoscopic stapling device has been provided that has room for a pair for longitudinal passageways for shoes on a cutter that resists both tensile and compressive jaw loadings.
• Furthermore, it is desirable to maintain other advantages of U.S. Pat. No. 5,465,895 to include a wedge sled integral to a staple cartridge, rather than having camming surfaces attached to a cutter. Thereby, fabrication of the cutter is simplified, as is installation of the staple cartridge. Significantly, an integral wedge sled may be designed specifically for each size and application of a staple cartridge, allowing the stapling and severing instrument increased number of uses. In particular, the thickness of the staple cartridge may be based on the desired tissue thickness. Also, the number and spacing of rows of staples may vary.
• US 6,109,500 is considered to represent the closest prior art with respect to the present invention and discloses a surgical device that applies parallel rows of surgical fasteners to body tissue and concomitantly forms an incision between the rows of staples during an endoscopic or laparoscopic surgical procedure.
• This device is generally similar to the device of the present invention, but the anvil slot does not define upper and lower inner surfaces, nor is a middle member disclosed which is slidable against the upper surface of the elongate channel.
• Consequently, a significant need exists for an improved surgical stapling and severing instrument that maintains proper spacing in its end effector to achieve proper stapling of the severed tissue, yet retains the advantages of a staple cartridge having an integral wedge sled.
Brief Summary of the Invention
• The invention overcomes the above-noted and other deficiencies of the prior art by providing a firing mechanism that affirmatively vertically spaces an end effector of a surgical stapling and severing instrument. Thus, the instrument structurally assures adequate spacing to achieve proper stapling, even in instances where too little tissue is clamped in the end effector.
• The present invention provides a surgical instrument as in appendedclaim 1.
• These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
Brief Description of the Figures
• The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
• FIG. 1 depicts a partially cut-away side elevation view of a surgical stapling and severing instrument in an open position.
• FIG. 2 depicts a cross-sectional side elevation detail view along the line 2-2 of FIG. 1 of an end effector of the surgical stapling and severing instrument.
• FIG. 3 depicts an enlarged side elevation view of the firing bar of the surgical stapling and severing instrument of FIG. 2.
• FIG. 4 depicts an enlarged front view of the firing bar of the surgical stapling and severing instrument of FIG. 2.
• FIG. 5 depicts a cross-sectional side elevation detail view of an alternative end effector for the surgical stapling and severing instrument of FIG. 1, incorporating a firing bar that lacks a middle pin for preventing pinching of the end effector.
• FIG. 6 depicts a side elevational view of a handle portion of a proximal end of the surgical stapling and severing instrument of FIG. 1 with a left side removed to expose interior parts in an unclamped, unfired ("start") position.
• FIG. 7 depicts a perspective, exploded view of the handle portion of the proximal end of the surgical stapling and severing instrument of FIG. 1.
• FIG. 8 depicts a side elevational view of the handle portion of the proximal end of the surgical stapling and severing instrument of FIG. 1 with the left side removed to expose interior parts in the closed ("clamped") position.
• FIG. 9 depicts a side elevational view of the handle portion of proximal end of surgical stapling and severing instrument of FIG. 1 with the left side removed to expose interior parts in the stapled and severed ("fired") position.
• FIG. 10 depicts an isometric view of the end effector at the distal end of the surgical stapling and severing instrument of FIG. 1 with the anvil in the up or open position exposing the staple cartridge and cutting edge of the firing bar.
• FIG. 11 depicts an isometric, exploded view of the implement portion of the surgical stapling and severing instrument of FIG. 1.
• FIG. 12 depicts an isometric view of the end effector at the distal end of the surgical stapling and severing instrument of FIG. 1 with the anvil in the up or open position with the cartridge largely removed exposing a single staple driver and a double staple driver as exemplary and the wedge sled in its start position against a middle pin of the firing bar.
• FIG 13 depicts an isometric view of the distal end of the surgical stapling and severing instrument of FIG. 1 with the anvil in the up or open position with the staple cartridge completely removed and a portion of an elongate channel removed to expose a lowermost pin of the firing bar.
• FIG. 14 depicts a side elevation view in section showing a mechanical relationship between the anvil, elongate channel, and staple cartridge in the closed position of the surgical stapling and severing instrument of FIG. 1, the section generally taken along lines 14-14 of FIG. 10 to expose wedge sled, staple drivers and staples but also depicting the firing bar along the longitudinal centerline.
• FIG. 15 depicts a section view of the end effector of the surgical stapling and severing instrument with the cartridge and firing bar in the start position taken along line 15-15 of FIG. 10.
• FIG. 16 depicts a section view taken along line 16-16 of Fig. 15 showing the cross-sectional relationship between the firing bar, elongate channel, wedge sled, staple drivers, staples and staple cartridge.
• FIG. 17 depicts a side elevation section view of the surgical stapling and severing instrument of FIG. 1 taken along the longitudinal centerline of the end effector in a partially closed but unclamped position gripping tissue.
• FIG. 18 depicts a partially cut-away side elevational view of the surgical stapling and severing instrument of FIG. 1 in the closed or clamped position.
• FIG. 19 depicts a side elevation view in centerline section of the distal end of the surgical stapling and severing instrument of FIG. 1 in the closed or clamped position with tissue properly compressed.
• FIG. 20 depicts a partially cut-away side elevation view of the surgical stapling and severing instrument of FIG. 1 in a partially fired position.
• FIG. 21 depicts a view in centerline section of the distal end of the surgical stapling and severing instrument of FIG. 1 in a partially fired position.
• FIG. 22 depicts a partially cut-away side elevation view of the surgical stapling and severing instrument of FIG. 1 in a fully fired position.
• FIG. 23 depicts a view in centerline section of the distal end of the surgical stapling and severing instrument of FIG. 1 in a fully fired position.
Detailed Description of the Invention
• Turning to the Drawings, wherein like numerals denote like components throughout the several views, FIG. 1 and 2 depict a surgical stapling and severinginstrument 10 that is capable of practicing the unique benefits of the present invention. The surgical stapling and severinginstrument 10 incorporates anend effector 12 having an E-beam firing mechanism ("firing bar") 14 that advantageously controls the spacing of theend effector 12. In particular, anelongate channel 16 and a pivotallytranslatable anvil 18 are maintained at a spacing that assures effective stapling and severing. The problems are avoided associated with varying amounts of tissue being captured in theend effector 12.
• The surgical and stapling and severinginstrument 10 includes ahandle portion 20 connected to an implementportion 22, the latter further comprising ashaft 23 distally terminating in theend effector 12. Thehandle portion 20 includes apistol grip 24 toward which aclosure trigger 26 is pivotally drawn by the clinician to cause clamping, or closing, of theanvil 18 toward theelongate channel 16 of theend effector 12. A firingtrigger 28 is farther outboard of theclosure trigger 26 and is pivotally drawn by the clinician to cause the stapling and severing of clamped tissue in theend effector 12.
• It will be appreciated that the terms "proximal" and "distal" are used herein with reference to a clinician gripping a handle of an instrument. Thus, theend effector 12 is distal with respect to the moreproximal handle portion 20. It will be further appreciated that for convenience and clarity, spatial terms such as "vertical" and "horizontal" are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.
• Closure trigger 26 is actuated first. Once the clinician is satisfied with the positioning of theend effector 12, the clinician may draw back theclosure trigger 26 to its fully closed, locked position proximate to thepistol grip 24. Then, the firingtrigger 28 is actuated. The firingtrigger 28 springedly returns when the clinician removes pressure. Arelease button 30 when depressed on the proximal end of thehandle portion 20 releases any lockedclosure trigger 26.
• Aclosure sleeve 32 encloses aframe 34, which in turn encloses afiring drive member 36 that is positioned by the firingtrigger 28. Theframe 34 connects thehandle portion 20 to theend effector 12. With theclosure sleeve 32 withdrawn proximally by theclosure trigger 26 as depicted, theanvil 18 springedly opens, pivoting away from theelongate channel 16 and translating proximally with theclosure sleeve 32.
• Theelongate channel 16 receives astaple cartridge 37 that is responsive to the firingbar 14 to drive staples into forming contact with theanvil 18. It will appreciated that although a readilyreplaceable staple cartridge 37 is advantageously described herein, astaple cartridge 37 consistent with aspects of the present invention may be permanently affixed or integral to theelongate channel 16, for instance when a larger portion of theend effector 12 is replaced after each firing.
• E-BEAM FIRING MECHANISM
• Of particular relevance to the presently claimed invention and with particular reference to FIGS. 2-4, the firingbar 14 includes three vertically spaced pins that control the spacing of theend effector 12 during firing. In particular, anupper pin 38 is staged to enter ananvil pocket 40 near the pivot between theanvil 18 andelongate channel 16. When fired with theanvil 18 closed, theupper pin 38 advances distally within alongitudinal anvil slot 42 extending distally throughanvil 18. Any minor upward deflection in theanvil 18 is overcome by a downward force imparted by theupper pin 38.
• Firingbar 14 also includes a lower most pin, or firing bar cap, 44 that upwardly engages theelongate channel 16, adjacent achannel slot 45 thereby cooperating with theupper pin 38 to draw theanvil 18 and theelongate channel 16 slightly closer together in the event of excess tissue clamped therebetween.
• The firingbar 14 advantageously includes amiddle pin 46 that passes through afiring drive slot 47 formed in a lower surface of thecartridge 37 and an upward surface of theelongate channel 16, thereby driving the staples therein as described below. Themiddle pin 46, by sliding against theelongate channel 16, advantageously resists any tendency for theend effector 12 to be pinched shut at its distal end. To illustrate an advantage of themiddle pin 46, FIG. 5 depicts an alternative end effector 12' that lacks a middle pin on a firing bar 14'. In this depiction, the end effector 12' is allowed to pinch shut at its distal end, which tends to impair desired staple formation.
• Returning to FIGS. 2-4, a distally presented cuttingedge 48 between the upper andmiddle pins 38, 46 on the firingbar 14 traverses through a proximally presented,vertical slot 49 in thecartridge 37 to sever clamped tissue. The affirmative positioning of the firingbar 14 with regard to theelongate channel 16 andanvil 18 assure that an effective cut is performed:
• CAMBERED ANVIL WITH SELECTED CARTRIDGE GAP
• The affirmative vertical spacing provided by theE-Beam firing bar 14 is suitable for the limited size available for endoscopic devices. Moreover, theE-Beam firing bar 14 enables fabrication of ananvil 16 with a camber imparting a vertical deflection at its distal end, similar to the position depicted in FIG. 5. Thiscambered anvil 16 advantageously assists in achieving the desired gap in theend effector 12 even with ananvil 16 reduced thickness, which is thus more suited to the size limitations of an endoscopic device.
• TheE-Beam firing bar 14 further enables increased applications, especially in combination with a range of configurations of staple cartridges. For instance, a clinician may select a gray staple cartridge yielding a 0.02 mm tissue gap, a white staple cartridge yielding a 0.04 mm tissue gap, a blue cartridge yielding a 0.06 mm tissue gap, or a green cartridge yielding a 0.10 mm tissue gap. The vertical height of each respective staple cartridge in combination with the length of staples and an integral wedge sled (described in more detail below) predetermines this desired tissue thickness with theanvil 18 appropriately vertically spaced by theE-Beam firing bar 14.
• TWO-AXIS HANDLE
• With reference to FIGS. 6-9, thehandle portion 20 is comprised of first andsecond base sections 50 and 52, which are molded from a polymeric material such as a glass-filled polycarbonate. Thefirst base section 50 is provided with a plurality of cylindrical-shaped pins 54. Thesecond base section 52 includes a plurality of extendingmembers 56, each having a hexagonal-shapedopening 58. The cylindrical-shapedpins 54 are received within the hexagonal-shapedopenings 58 and are frictionally held therein for maintaining the first andsecond base sections 50 and 52 in assembly.
• A rotatingknob 60 has abore 62 extending completely through it for engaging and rotating the implementportion 22 about its longitudinal axis. The rotatingknob 60 includes an inwardly protrudingboss 64 extending along at least a portion of thebore 62. The protrudingboss 64 is received within alongitudinal slot 66 formed at a proximal portion of theclosure sleeve 32 such that rotation of therotating knob 60 effects rotation of theclosure sleeve 32. It will be appreciated that theboss 64 further extends throughframe 34 and into contact with a portion of the firingdrive member 36 to effect their rotation as well. Thus, the end effector 12 (not shown in FIGS. 6-9) rotates with the rotatingknob 60.
• Aproximal end 68 of theframe 34 passes proximally through the rotatingknob 60 and is provided with acircumferential notch 70 that is engaged by opposing channel securement members 72 extending respectively from thebase sections 50 and 52. Only the channel securement member 72 of thesecond base section 52 is shown. The channel securement members 72 extending from thebase sections 50, 52 serve to secure theframe 34 to thehandle portion 20 such that theframe 34 does not move longitudinally relative to thehandle portion 20.
• Theclosure trigger 26 has ahandle section 74, agear segment section 76, and anintermediate section 78. A bore 80 extends through theintermediate section 78. Acylindrical support member 82 extending from thesecond base section 52 passes through thebore 80 for pivotably mounting theclosure trigger 26 on thehandle portion 20. A secondcylindrical support member 83 extending from thesecond base section 52 passes through abore 81 of firingtrigger 28 for pivotally mounting on thehandle portion 20. Ahexagonal opening 84 is provided in thecylindrical support member 83 for receiving a securement pin (not shown) extending from thefirst base section 50.
• Aclosure yoke 86 is housed within thehandle portion 20 for reciprocating movement therein and serves to transfer motion from theclosure trigger 26 to theclosure sleeve 32.Support members 88 extending from thesecond base section 52 and securement member 72, which extends through arecess 89 in theyoke 86, support theyoke 86 within thehandle portion 20.
• Aproximal end 90 of theclosure sleeve 32 is provided with aflange 92 that is snap-fitted into a receivingrecess 94 formed in adistal end 96 of theyoke 86. Aproximal end 98 of theyoke 86 has agear rack 100 that is engaged by thegear segment section 76 of theclosure trigger 26. When theclosure trigger 26 is moved toward thepistol grip 24 of thehandle portion 20, theyoke 86 and, hence, theclosure sleeve 32 move distally, compressing aspring 102 that biases theyoke 86 proximally. Distal movement of theclosure sleeve 32 effects pivotal translation movement of theanvil 18 distally and toward theelongate channel 16 of theend effector 12 and proximal movement effects closing, as discussed below.
• Theclosure trigger 26 is forward biased to an open position by afront surface 130 interacting with anengaging surface 128 of the firingtrigger 28. Clampfirst hook 104 that pivots top to rear in thehandle portion 20 about apin 106 restrains movement of the firingtrigger 28 toward thepistol grip 24 until theclosure trigger 26 is clamped to its closed position.Hook 104 restrains firingtrigger 28 motion by engaging alockout pin 107 in firingtrigger 28. Thehook 104 is also in contact with theclosure trigger 26. In particular, aforward projection 108 of thehook 104 engages amember 110 on theintermediate section 78 of theclosure trigger 26, themember 110 being outward of thebore 80 toward thehandle section 74.Hook 104 is biased toward contact withmember 110 of theclosure trigger 26 and engagement withlockout pin 107 in firingtrigger 28 by arelease spring 112. As theclosure trigger 26 is depressed, thehook 104 is moved top to rear, compressing therelease spring 112 that is captured between arearward projection 114 on thehook 104 and aforward projection 116 on therelease button 30.
• As theyoke 86 moves distally in response to proximal movement of theclosure trigger 26, anupper latch arm 118 of therelease button 30 moves along anupper surface 120 on theyoke 86 until dropping into an upwardly presentedrecess 122 in a proximal, lower portion of theyoke 86. Therelease spring 112 urges therelease button 30 outward, which pivots theupper latch arm 118 downwardly into engagement with the upwardly presentedrecess 122, thereby locking theclosure trigger 26 in a tissue clamping position, such as depicted in FIG. 8.
• Thelatch arm 118 can be moved out of therecess 122 to release theanvil 18 by pushing therelease button 30 inward. Specifically, theupper latch arm 118 pivots upward aboutpin 123 of thesecond base section 52. Theyoke 86 is then permitted to move proximally in response to return movement of theclosure trigger 26.
• A firingtrigger return spring 124 is located within thehandle portion 20 with one end attached to pin 106 of thesecond base section 52 and the other end attached to apin 126 on the firingtrigger 28. The firingreturn spring 124 applies a return force to thepin 126 for biasing the firingtrigger 28 in a direction away from thepistol grip 24 of thehandle portion 20. Theclosure trigger 26 is also biased away frompistol grip 24 by engagingsurface 128 of firingtrigger 28 biasingfront surface 130 ofclosure trigger 26.
• As theclosure trigger 26 is moved toward thepistol grip 24, itsfront surface 130 engages with theengaging surface 128 on the firingtrigger 28 causing the firingtrigger 28 to move to its "firing" position. When in its firing position, the firingtrigger 28 is located at an angle of approximately 45° to thepistol grip 24. After staple firing, thespring 124 causes the firingtrigger 28 to return to its initial position. During the return movement of the firingtrigger 28, its engagingsurface 128 pushes against thefront surface 130 of theclosure trigger 26 causing theclosure trigger 26 to return to its initial position. Astop member 132 extends from thesecond base section 52 to prevent theclosure trigger 26 from rotating beyond its initial position.
• The surgical stapling and severinginstrument 10 additionally includes areciprocating section 134, amultiplier 136 and adrive member 138. Thereciprocating section 134 comprises a wedge sled in the implement portion 22 (not shown in FIG. 6-9) and ametal drive rod 140.
• Thedrive member 138 includes first and second gear racks 141 and 142. Afirst notch 144 is provided on thedrive member 138 intermediate the first and second gear racks 141, 142. During return movement of the firingtrigger 28, atooth 146 on the firingtrigger 28 engages with thefirst notch 144 for returning thedrive member 138 to its initial position after staple firing. Asecond notch 148 is located at a proximal end of themetal drive rod 140 for locking themetal drive rod 140 to theupper latch arm 118 of therelease button 30 in its unfired position.
• Themultiplier 136 comprises first and second integral pinion gears 150 and 152. The firstintegral pinion gear 150 is engaged with afirst gear rack 154 provided on themetal drive rod 140. The secondintegral pinion gear 152 is engaged with thefirst gear rack 141 on thedrive member 138. The firstintegral pinion gear 150 has a first diameter and the secondintegral pinion gear 152 has a second diameter which is smaller than the first diameter.
• FIGS. 6, 8 and 9 depict respectively thehandle portion 20 in the start position (open and unfired), a clamped position (closed and unfired) and a fired position. The firingtrigger 28 is provided with agear segment section 156. Thegear segment section 156 engages with thesecond gear rack 142 on thedrive member 138 such that motion of the firingtrigger 28 causes thedrive member 138 to move back and forth between a first drive position, shown in FIG. 8, and a second drive position, shown in FIG. 9. In order to prevent staple firing before tissue clamping has occurred, theupper latch arm 118 on therelease button 30 is engaged with thesecond notch 148 on thedrive member 138 such that themetal drive rod 140 is locked in its proximal-most position, as depicted in FIG. 6. When theupper latch arm 118 falls into therecess 122, theupper latch arm 118 disengages with thesecond notch 148 to permit distal movement of themetal drive rod 140, as depicted in FIG. 9.
• Because thefirst gear rack 141 on thedrive member 138 and thegear rack 154 on themetal drive rod 140 are engaged with themultiplier 136, movement of the firingtrigger 28 causes themetal drive rod 140 to reciprocate between a first reciprocating position, shown in FIG. 8, and a second reciprocating position, shown in FIG. 9. Since the diameter of thefirst pinion gear 150 is greater than the diameter of thesecond pinion gear 152, themultiplier 136 moves the reciprocating section 134 a greater distance than thedrive member 138 is moved by the firingtrigger 28. The diameters of the first and second pinion gears 150 and 152 may be changed to permit the length of the stroke of the firingtrigger 28 and the force required to move it to be varied.
• It will be appreciated that thehandle portion 20 is illustrative and that other actuation mechanisms may be employed. For instance, the closing and firing motions may be generated by automated means.
• SEPARATE AND DISTINCT CLOSING AND FIRING END EFFECTOR
• Theend effector 12 of the surgical stapling and severinginstrument 10 is depicted in further detail in FIGS. 10-16. As described above, thehandle portion 20 produces separate and distinct closing and firing motions that actuate theend effector 12. Theend effector 12 advantageously maintains the clinical flexibility of this separate and distinct closing and firing (i.e., stapling and severing). In addition, theend effector 12 introduces the aforementioned ability to affirmatively maintain the closed spacing during firing after the clinician positions and clamps the tissue. Both features procedurally and structurally enhance the ability of the surgical stapling and severinginstrument 10 by ensuring adequate spacing for instances where an otherwise inadequate amount of tissue is clamped and to enhance the clamping in instances where an otherwise excessive amount of tissue has been clamped.
• FIG. 10 depicts theend effector 12, which is in an open position by a retractedclosure sleeve 32, with astaple cartridge 37 installed in theelongate channel 16. On alower surface 200 of theanvil 18, a plurality ofstapling forming pockets 202 are arrayed to correspond to a plurality ofstapler apertures 204 in anupper surface 206 of thestaple cartridge 37. The firingbar 14 is at its proximal position, with theupper pin 38 aligned in a noninterfering fashion with theanvil pocket 40. Theanvil pocket 40 is shown as communicating with thelongitudinal anvil slot 42 in theanvil 18. The distally presented cuttingedge 48 of the firingbar 14 is aligned with and proximally from removed from thevertical slot 49 in thestaple cartridge 37, thereby allowing removal of a spent cartridge and insertion of an unfired cartridge, which is snapfit into theelongate channel 16. Specifically, extension features 208, 210 of thestaple cartridge 37 engagerecesses 212, 214 (shown in FIG. 12) of theelongate channel 16.
• FIG. 11 shows the implementportion 22 of the surgical stapling and severinginstrument 10 in disassembled form. Thestaple cartridge 37 is shown as being comprised of acartridge body 216, awedge sled 218, single anddouble drivers 220,staples 222, and acartridge tray 224. When assembled, thecartridge tray 224 holds thewedge sled 218, single anddouble drivers 220, andstaples 222 inside thecartridge body 216.
• Having awedge sled 218 integral to thestaple cartridge 37 enables a number of flexible design options as compared to incorporating camming surfaces onto a firing bar itself. For instance, a number of different staple cartridges may be selected for use in theinstrument 10 with each staple cartridge having a different configuration of rows of staples, each thus having a unique wedge sled configured to contact themiddle pin 46 of the firingbar 14 while causing the driving of thestaples 222. As another example, theintegral wedge sled 218 provides an opportunity for a number of lockout features, described in greater detail in the first and third aforementioned co-pending applications.
• Theelongate channel 16 has a proximally placedattachment cavity 226 that receives achannel anchoring member 228 on the distal end of theframe 34 for attaching theend effector 12 to thehandle portion 20. Theelongate channel 16 also has ananvil cam slot 230 that pivotally receives ananvil pivot 232 of theanvil 18. Theclosure sleeve 32 that encompasses theframe 34 includes a distally presentedtab 234 that engages ananvil feature 236 proximate but distal to theanvil pivot 232 on theanvil 18 to thereby effect opening and closing of theanvil 18. The firingdrive member 36 is shown as being assembled from the firingbar 14 attached to afiring connector 238 bypins 240, which in turn is rotatingly and proximally attached to themetal drive rod 140. The firingbar 14 is guided at a distal end of the frame by a slottedguide 239 inserted therein.
• With particular reference to FIG. 12, a portion of thestaple cartridge 37 is removed to expose portions of theelongate channel 16, such asrecesses 212, 214 and to expose some components of thestaple cartridge 37 in their unfired position. In particular, the cartridge body 216 (shown in FIG. 11) has been removed. Thewedge sled 218 is shown at its proximal, unfired position with apusher block 242 contacting the middle pin 46 (not shown in FIG. 12) of the firingbar 14. Thewedge sled 218 is in longitudinal sliding contact upon thecartridge tray 224 and includeswedges 228 that force upward the single anddouble drivers 220 as thewedge sled 218 moves distally. Staples 222 (not shown in FIG. 12) resting upon thedrivers 220 are thus also forced upward into contact with theanvil forming pockets 202 on theanvil 18 to form closed staples. Also depicted is thechannel slot 45 in theelongate channel 16 that is aligned with thevertical slot 49 in thestaple cartridge 37.
• FIG. 13 depicts theend effector 12 of FIG. 12 with all of thestaple cartridge 37 removed to show themiddle pin 46 of the firingbar 14 as well as portion of theelongate channel 16 removed adjacent to thechannel slot 45 to expose the firingbar cap 44. In addition, portions of theshaft 23 are removed to expose a proximal portion of the firingbar 14. Projecting downward from theanvil 18 near the pivot, a pair of opposing tissue stops 244 prevent tissue being positioned too far up into theend effector 12 during clamping.
• FIG. 14 depicts theend effector 12 closed in a tissue clamping position with the firingbar 14 unfired. Theupper pin 38 is in theanvil pocket 40, vertically aligned with theanvil slot 42 for distal longitudinal movement of the firingbar 14 during firing. Themiddle pin 46 is positioned to push thewedge sled 218 distally so thatwedge 228 sequentially contacts and liftsdouble drivers 220 and therespective staples 222 into forming contact withstaple forming pockets 202 in thelower surface 200 of theanvil 18.
• FIG. 15 depicts theupper surface 206 of thestaple cartridge 37 with the firingbar 14 in its unfired, proximal position. Thestapler apertures 204 are arrayed on each side of thevertical slot 49 in thestaple cartridge 37.
• FIG. 16 depicts theend effector 12 near the pivot showing that theelongate channel 16 has opposingramp portions 246 to thereby cooperate with the tissue stops 244 of the anvil 18 (not shown in FIG. 16) to prevent tissue from jamming theend effector 12. Also depicted in greater detail are thedouble drivers 220 and their relation to thestaples 222.
• OPERATION
• In use, the surgical stapling and severinginstrument 10 is used as depicted in FIGS 1, 2, and 17-23. In FIGS. 1-2, theinstrument 10 is in its start position, having had an unfired, fully loadedstaple cartridge 37 snap-fitted into the distal end of theelongate channel 16. Both triggers 26, 28 are forward and theend effector 12 is open, such as would be typical after inserting theend effector 12 through a trocar or other opening into a body cavity. Theinstrument 10 is then manipulated by the clinician such thattissue 248 to be stapled and severed is positioned between thestaple cartridge 37 and theanvil 18, as depicted in FIG. 17.
• With reference to FIGS. 18-19, next, the clinician moves theclosure trigger 26 proximally until positioned directly adjacent to thepistol grip 24, locking thehandle portion 20 into the closed and clamped position. The retractedfiring bar 14 in theend effector 12 does not impede the selective opening and closing of theend effector 12, but rather resides within theanvil pocket 40. With theanvil 18 closed and clamped, theE-beam firing bar 14 is aligned for firing through theend effector 12. In particular, theupper pin 38 is aligned with theanvil slot 42 and theelongate channel 16 is affirmatively engaged about thechannel slot 45 by themiddle pin 46 and the firingbar cap 44.
• With reference to FIGS. 20-21, after tissue clamping has occurred, the clinician moves the firingtrigger 28 proximally causing the firingbar 14 to move distally into theend effector 12. In particular, themiddle pin 46 enters thestaple cartridge 37 through the firingdrive slot 47 to effect the firing of the staples 222 (not shown in FIGS. 20-21) viawedge sled 218 toward theanvil 18. The lower most pin, or firingbar cap 44, cooperates with themiddle pin 46 to slidinglyposition cutting edge 48 of the firingbar 14 to sever tissue. The twopins 44, 46 also position theupper pin 38 of the firingbar 14 withinlongitudinal anvil slot 42 of theanvil 18, affirmatively maintaining the spacing between theanvil 18 and theelongate channel 16 throughout its distal firing movement.
• With reference to FIGS. 22-23, the clinician continues moving the firingtrigger 28 until brought proximal to theclosure trigger 26 andpistol grip 24. Thereby, all of the ends of thestaples 222 are bent over as a result of their engagement with theanvil 18. The firingbar cap 44 is arrested against a firingbar stop 250 projecting toward the distal end of thechannel slot 45. Thecutting edge 48 has traversed completely through the tissue. The process is complete by releasing the firingtrigger 28 and by then depressing therelease button 30 while simultaneously squeezing theclosure trigger 26 to open theend effector 12.
• While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.
• For example, the affirmative spacing of theanvil 18 andelongate channel 16 is achieved in part with twopins 44, 46 on the firingbar 14 engaging opposite sides of achannel slot 47 and a singleupper pin 38 entrained within ananvil slot 42.
• For another example, although theE-beam firing beam 14 has advantages for an endoscopically employed surgical severing and staplinginstrument 10, a similar E-Beam may be used in other clinical procedures. It is generally accepted that endoscopic procedures are more common than laparoscopic procedures. Accordingly, the present invention has been discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as "endoscopic", should not be construed to limit the present invention to a surgical stapling and severing instrument for use only in conjunction with an endoscopic tube (i.e., trocar). On the contrary, it is believed that the present invention may find use in any procedure where access is limited to a small incision, including but not limited to laparoscopic procedures, as well as open procedures.
• For yet another example, although anillustrative handle portion 20 described herein is manually operated by a clinician, it is consistent with aspects of the invention for some or all of the functions of a handle portion to be powered (e.g., pneumatic, hydraulic, electromechanical, ultrasonic, etc.). Furthermore, controls of each of these functions may be manually presented on a handle portion or be remotely controlled (e.g., wireless remote, automated remote console, etc.).

Claims (5)

1. A surgical stapling instrument (10) comprising:

   a handle portion (20) operable to produce a firing motion;

   an implement portion (22) responsive to the firing motions from the handle portion (20), the implement portion (22) comprising:

   an elongate channel (16) coupled to the handle portion (20) and including a channel slot (45),

   a staple cartridge (37) received by the elongate channel (16) and incorporating a proximally positioned wedge member aligned to cam upward a driver (220) supporting a staple (222),

   an anvil (18) pivotally coupled to the elongate channel (16) and including an anvil slot (42) defining upper and lower inner surfaces extending substantially along the longitudinal length of the anvil (18),

   a firing device including a distally presented cutting edge (48) longitudinally received between the elongate channel (16) and the anvil (18), an upper member (38) comprised of an upper pin slidably engageable with the upper and lower inner surfaces of the anvil channel (18), a lower member (44) upwardly engagable with the elongate channel (16) adjacent the channel slot (45), and a middle member (46) operable to actuate the staple cartridge (37) by distally translating the wedge member of the staple cartridge (37) and slidable against an upper surface of the elongate channel (16), such that the firing device positively engages both the elongate channel (16) and the anvil (18) during longitudinal firing travel to maintain vertical spacing between the elongate channel (16) and the anvil (18), thus resisting both a pinching together and a forcing apart of the elongate channel (16) and the anvil (18).
2. The surgical instrument of claim 1, wherein:

   the handle portion is further operable to produce a closing motion;

   the implement portion is diametrically dimensioned for endo-surgical use, and the implement portion further comprises:

   a shaft coupled to the handle portion operable to separately transfer the firing motion and the closing motion; wherein

   the elongate channel is coupled to the shaft, and

   the anvil is responsive to the closing motion from the shaft.
3. The surgical instrument of claim 2, wherein the staple cartridge includes a proximally opened slot for receiving the cutting edge of the firing device, the staple cartridge including a plurality of staples arranged so as to be cammed upwardly by the distal longitudinal movement of the firing mechanism.
4. The surgical instrument of claim 3, wherein the staple cartridge further includes a plurality of drivers supporting the plurality of staples and the wedge member comprises a wedge sled responsive to the distal longitudinal movement of the firing mechanism to cam upwardly the drivers and thus form the plurality of staples against the anvil.
5. The surgical instrument of claim 3, wherein the wedge member comprises a wedge sled (218) having a plurality of connected camming wedges (228) each having a preselected height configured for a selected type of staple cartridge (37), the middle member (46) of the firing device oriented to abut each of the plurality of staple cartridge types.

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